GREEN BAY – Playing offensive line for the Green Bay Packers is a different animal from what it was the last time center Corey Linsley snapped a ball to quarterback Aaron Rodgers.

Before landing on the physically unable to perform list with a hamstring injury, Linsley was preparing for a season in which coach Mike McCarthy would feed Eddie Lacy and James Starks the ball enough to get their jerseys dirty every week.

In the three months since the start of training camp, Linsley has watched from the sideline as his fellow offensive linemen have become engaged in a perpetual pass-rush drill, the result of the Packers' offense morphing into a four- and five-receiver attack.

Linsley will be activated this week and start Sunday against the Indianapolis Colts because starting center JC Tretter has a knee injury that will sideline him several weeks, according to a source familiar with the injury.

Over his first two seasons, Linsley has started 33 games, losing his job only because he suffered a major hamstring injury during the offseason. However, the last time he put on a game jersey, he was preparing for Lacy or Starks to run behind him a good portion of the time.

“It looks different and we operate a little bit different,” Linsley said of the changes since he has been gone. “But it's the same stuff (scheme) that we've been going through, although for us, as O-linemen, it's adjusting to passing as much (as they are).”

They aren’t complaining about it – at least not publicly – but McCarthy’s starting five has taken on a great burden since Lacy and Starks bowed out with injuries after the Dallas game and the offense began employing a spread look.

Consider:

Last season, the Packers did not run a single play out of a five-receiver/empty backfield look in 16 regular-season and two playoff games. They ran plays out of four-receiver sets 83 times.

In seven games this season, they already have lined up empty 35 times. They have lined up in four-receiver sets 107 times.

As much as McCarthy resists having his offense labeled “spread," the Packers are mostly that because they don’t have a lead running back. Receiver Ty Montgomery is their primary back until Starks returns and the most carries he has had in a single game is nine against Chicago.

The Packers rank 11th in the NFL in percentage of pass plays (62.96) and over the past two games are at 75.2 percent if you count Rodgers’ scrambles as pass attempts. McCarthy is trying to figure out how to run the ball with some combination of Montgomery, rookie Don Jackson and fullback Aaron Ripkowski, but it’s no secret the Packers are going to pass a lot Sunday against Indianapolis.

“Every week starts up front,” McCarthy said of his intention to run the ball. “The meetings still start the same. We start with the run game, the protections and the pressures, and then move on to the passing game.

“So we're not a spread offense, so don't ever say that again in here.”

McCarthy was smiling when he made that comment to a reporter in his news conference Wednesday, but the point is, playing that way has been a weekly response to injuries in the backfield.

For the offensive line, it creates a lot of stress to go into a week thinking they might be running the ball some and wind up passing it 40 times on Sunday. Luckily for McCarthy, he has the offensive line to handle having Rodgers line up in shotgun formation and throw pass after pass.

“It’s a lot of stress, but really it’s one of those challenges where we believe we’re the best pass-blocking unit in the league and it’s that kind of league and so we’re going to have to go out and execute it,” left tackle David Bakhtiari said. “They (defensive linemen) get to tee off on us.

“But we have to execute no matter how much pressure they put on us.”

The Packers rank 11th in the NFL in fewest sacks allowed per pass play (14 in 289) and seventh in fewest holding penalties with 10 (six committed by offensive linemen). Rodgers has taken a hefty number of hits, but a good portion of them came after he left the pocket.

“We’ve done a pretty good job this year, keeping Aaron clean, giving him time,” guard Lane Taylor said. “We’ve helped Aaron out and he’s helped us out at times. We do a good job playing off each other and playing well.”

Taylor acknowledged that opposing defensive linemen benefit from knowing the Packers aren’t going to run the ball, especially when they’re in an empty formation. But he said even though they don’t have to worry about playing the run, the Packers’ offensive linemen know exactly what they’re going to be doing.

“You just have to go with it,” Taylor said. “It’s going to be one of those games. It’s going to be a long pass-blocking period just like in practice. You know what they’re doing and they know what you’re doing, so you just get after it.”

It’s no secret that most offensive linemen love to run the ball. Besides keeping the defensive linemen honest, it spares them the finesse part of their job and lets them slug it out in the trenches.

But to be good at running the ball, you generally have to do it a lot. The Packers don’t do it much at all, so what happens when Starks gets healthy, the weather gets colder and they start to switch back to a more traditional offense?